What we did do was examine a range of options for US forward presence in the Pacific and score them based on four criteria: geostrategic, operational, affordability and executability. We concluded that a second US carrier battle group in the Pacific would certainly have operational merit, but scored it negatively in terms of affordability and executability and in the end it did not make the cut for our final set of recommendations to the US Congress and Department of Defense. That is not to say that moving more US Navy assets to HMAS Sterling should be off the table, but we did not think a second huge nuclear powered carrier battle group should be part of US planning at this point.

(A link to the full report and the cover letter provided to Congress by Secretary of Defense Panetta can be found on the website of Senator Carl Levin. CSIS will shortly put a more easily downloadable copy on our website, pending final approval from the Pentagon.)

In this project, CSIS went through an intensive review of our current, planned and potential options for force posture, aided by a group of outside advisers that included Rich Armitage, Andrew Shearer, former PACOM Commander Tim Keating, and others. I co-directed the effort with David Berteau, Senior Vice President and head of security studies at CSIS. Our debate and discussion on a second carrier battle group touched on many of the factors that we concluded need to shape our strategy.

First, while it is a sine qua non that the US must retain credible military forces to deter and if necessary defeat aggression in the region, our force posture cannot be guided purely by our war plans. At least as important will be the role US and allied forces play in shaping the strategic environment in peacetime. Forward deployed forces can lead in building regional patterns of cooperation on missions ranging from counter-piracy to humanitarian and disaster relief, and that includes increased participation by the PLA as these cooperative security practices take hold.

Our defence engagement with the Philippines and other strategically exposed states can ensure that they do not become targets of external coercion and that they have minimum necessary levels of maritime domain awareness needed to keep the overall strategic equilibrium stable. Expanded interoperability and planning among US allies — particularly Japan and Australia — can enhance dissuasion by demonstrating that like-minded states are ready to operate together without moving to a broader NATO-like collective security arrangement in the region that might prove too confrontational given the region's economic interdependence and community-building efforts.

A key lesson for the US is that if we ask for too much from allies and partners in terms of access and defence cooperation, we risk either a security dilemma with China or defections from states that want a stronger US presence but not military competition with their major trading partner.

At the same time, there is no doubt that virtually every major power in the region wants more of a relationship with US forces and that we are pushing on an open door. In that, there is a valuable lesson for Beijing in the wake of increased tensions in the East and South China Seas in recent years. This is a delicate balancing act. While the US does not specialise in being subtle, we can do well if we listen closely to our closest friends and allies, since they know the tipping points best of all.

None of this strategic shaping can happen without credible deterrence. If US forces are well positioned to engage in low-end humanitarian and policing missions but cannot defeat North Korean aggression or execute security commitments to our allies facing growing and intimidating PLA presence, then those allies and partners will be tempted either to bandwagon in ways that would shake the region's strategic equilibrium or hedge in ways that open new avenues for confrontation and crisis.

In our study we concluded that the US forward posture needs some adjustment along the lines planned by the Department of Defense to fill both the shaping and deterrence missions. The deployment of US Marines to Darwin is a good example of what those adjustments can bring in terms of joint bilateral and multilateral training opportunities and better geographic distribution.

At the same time, we also found fault with how the Department is explaining its strategy internally, to the Congress, and to the region. In our view it is better to be candid about our objectives than to avoid talking about the China dimension and thus leave the airwaves full of confusing sound bites about AirSea battle and the like.

In addition, we drew great confidence from the continued US military lead in the region, but found some areas where the US can enhance capabilities within realistic budget limitations. For example, we argued that the Navy needs a second amphibious ready group in the Pacific (probably on the West Coast or Hawaii) to give the Marines the lift and maneuver support they will need in a more dispersed laydown. We also need more missile defence and would benefit from additional attack submarines, since undersea warfare remains the US (and for that matter, Australian) trump card.

Speaking for myself and not necessarily my co-authors or outside advisers, I do worry about two variables not assessed directly in our report. The first is the defence budget debate in the US. The Administration has stated that sequestration (under the budget control act) and automatic defence cuts across the board would be debilitating for US strategy. It certainly would. Most inside observers think the Congress and Administration will either avoid a sequestration or fix things in the new year if they do end up with forced cuts. But if the strategy is to shape regional perceptions, this is no time for the Administration or Congress to play public games of chicken. We should be doing whatever we can to ensure that the US does not become the big variable in the future calculations of the region.

The second concern is the unexpected and unnecessary deep cuts in the Australian defence budget. I know that I am hardly alone in worrying that this will send the wrong strategic signals to the region. We do not need or want Australia to be a strategic variable ether.

The CSIS study represented an intensive effort over a short period of time. We probably raised as many questions as we answered and look forward to continued debate and discussion.